Hello, Thank you for your query. The lungs are normally seen as air filled (dark spaces) on the x-ray. The smaller airways (within the lungs) expand and contract when air goes in and out as we breathe. In certain conditions like asthma or bronchitis or long standing infection, these airways can be partially blocked and lead to air trapping. This means that we can breathe in the air but cannot breathe it all out again. Normally some amount of air remains to keep the airways open. In hyperaeration, this air that remains after we breathe out is increased and distended the airways which can be seen on an x-ray. In your son s x-ray, this seems to be getting better. Pleural effusion is fluid collection around the lung which had been completely resolved. The diaphragm and the space between the lung and diaphragm is also normal. He is getting better and there is nothing to worry or do. Just continue as is. Hope this helps. Please let me know if there is anything else I can help you with. Wish you all good health